Bubiacea; it attains thirty feet in height when allowed to grow, but is usually cut down to the ordinary height of a man, to increase the crop of fruit. The fruit is a two-seeded berry, similar in appearance and colour to a small cherry; each berry contains two coffee beans in a fleshy or parchment-like integument. As the fruit does not all ripen at the same time, one crop requires several gatherings; the fleshy part of the berry, which contains a considerable quantity of saccharine juice, is removed partly by mechanical agency, and partly by fermentation. The fresh, ripe berries are pressed between rollers, and their thick juice allowed to run through sieves; they are afterwards cleaned by washing with water, and are subsequently dried. All that remains to be done is to remove the skin from the seeds, by submitting them to the action of a heavy wooden wheel, and winnowing the chaff by a fan, as in the case of ordinary grain. In Venezuela, however, the plan followed is different; the berries are there spread out upon hurdles in the sun, where they undergo the vinous fermentation for fourteen or twenty days, and then dry. The beans are freed from the skins by a mill, and by subsequent winnowing.

The use of coffee dates in Arabia from the end of the fifteenth century; it was introduced into Paris in the year 1669, and the first coffee-house was opened by Arminier, at St. Germain, in 1672.

Structure of the coffee seed.-The coffee seed is composed of two parts, the substance of the seed, and the testa, or membrane by which it is surrounded.

The seed consists of an assemblage of vesicles or cells, of an angular form, and adhering firmly together. The cavities of the cells include a considerable quantity of aromatic volatile oil, on which the fragrance of the coffee mainly depends.

GENERAL LIBRARY

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The investing membrane is made up principally of elongated cells, forming a single layer, and having oblique mark

ings upon their surface; these cells rest upon another thin membrane, which presents an indistinct fibrous structure.

The roasting of the berry does not alter materially its structure; the essential oil, however, is no longer visible in

the cells in the form of minute drops or spherules, and has become more generally diffused throughout the cavities of the cells.

The following are the characters of the most important kinds of coffee, samples of which were kindly forwarded to me by a friend, one of our City brokers. The alphabetical order shows the relative value of the various coffees, commencing with those kinds which fetch the highest price.

A. Mocha coffee. - Light coloured, greenish-brown; partly or entirely covered with the husk; grains differ from each other in size and form, and have no regular shape; some grains are cracked or broken up.

E. Madras coffee.-Grains, coloured light green, are all of the same size, and have a regular form; they are not broken up, and are partly or entirely covered with an investing membrane, which is finer than in the case of Mocha coffee, and which adheres strongly to the seed. The grains have a shrivelled appearance.

G. Ceylon coffee (native).-Grains are larger than the preceding, and of a light yellowish-green colour, some grains being cracked or broken up; the husk is occasionally wanting, and does not adhere strongly to the seed; some grains are studded with dark green spots; the seeds differ from each other in size.

F. Mysore coffee (Bombay).-Grains have an elliptic shape; differ from each other as to their size; are partly covered with a slightly adhering husk; colour light green. Grains not shrivelled, or much broken up.

H. Brazil coffee (Rio).-Grains are somewhat misshapen, have a light green colour; husk wanting, or very fine, and strongly adhering to the grains; they are nearly all of the same size; some of them elliptic, others flattened, a few being small and shrivelled up.

I. Brazil coffee (Bahia).—Grains irregularly formed; colour. light yellowish-green, studded with dark green

spots; husks wanting in many grains, in others it does not adhere strongly, and has a coarse structure. Grains cracked or broken up; some are elliptic, others flattened; the elliptic grains are smaller and darker coloured than the flat ones.

D. Costa Rica coffee (America).-Grains are all of the same size and shape, i. e., rather flattened; colour uniformly light green; seeds nearly quite devoid of husk, are peculiarly smooth.

B. Ceylon coffee (Plantation Peaberry).-Grains small, and remarkably elliptical, are all of the same size, of a dark green colour, and partly covered with a thin husk.

C. Ceylon coffee (Plantation). Colour dark green; grains resembling each other in size and shape; their under surface is concave; every grain is partly covered with husk; size rather above the average.

Chemical composition and analysis of coffee.-Professor Rochleder, who has devoted great attention to the analysis of coffee, gives the following enumeration of the substances found in raw coffee-beans, with the formula of their elementary composition :

Payen enumerates the proportional quantities of the different substances which he finds in raw coffee, as follows:

1. Cellular tissue is the insoluble residue obtained by exhausting ground coffee with water and alcohol.

2. Hygroscopic water is detected, and its quantity determined by weighing the ground substance, drying it in the water bath, and ascertaining the loss.

3. Fats are obtained and determined by treating the ground coffee with ether, and evaporating the solution to dryness or by treating the crushed coffee beans with alcohol, and mixing the extract with water, when the fatty matters are precipitated.

4. Starch, sugar, and dextrine.—For starch, proceed as in the case of grains (p. 14). (For sugar and dextrine, employ the method described at pp. 8 and 9.)

5. Chlorogenate of potash and caffein.-It is doubtful whether this combination exists. To detect the presence of caffein or thein, let the analyst adopt the same means as recommended in the case of the extraction of thein from tea (p. 80).

Chlorogenic acid is the same as the caffeic or tannocaffeic acid of Rochleder and Pfaff. To obtain this acid, dried and crushed coffee beans are treated with alcohol, and the extract is mixed with water, and filtered, in order to